In a vacuum apparatus used in manufacturing a semiconductor, a thin film, a liquid crystal, or the like, a gate valve for opening/closing each vacuum chamber is employed.
In related art, various kinds of gate valves for vacuum apparatuses are known. For example, an inflation-sealing member is used when closing a valve, so that a sealing performance is enhanced (see, for example, Patent Documents 1 and 2). In addition, a pendulum gate valve or the like is also known.
FIGS. 5 and 6 show an example of a pendulum gate valve. In a pendulum gate valve 200 in related art, an opening 204b is formed on a sidewall 202b of a valve casing 202, as viewed from a front thereof (FIG. 6). The valve 200 further includes a valve chamber 215 formed between a sidewall 202a and the sidewall 202b facing each other, a pendulum valve body 203 provided in the valve chamber 215, and a sealing ring 205, as viewed inside the valve casing 202 from a side thereof. On the sidewalls 202a and 202b facing each other, an opening 204a and the opening 204b are formed. To the sealing ring 205, ring-shaped sealing members 206 and 207 are attached (FIG. 5).
When closing the valve 200 in an open state, an air actuator 209 provided on a side of the valve casing 202 is driven by using an air pressure, and an actuator shaft 208 is rotated to move the pendulum valve body 203 up to in front of the opening 204a, i.e., a valve closing, position. Then, an air cylinder 211 is driven by using the air pressure to move a shaft 210, and the sealing ring 205 is pressed against the valve body 203. Thus, in the valve casing 202, the sealing member 207 seals a gap between an inner wall surface around the opening 204b and the sealing ring 205, and the sealing member 206 seals a gap between a surface of the valve body 203 and the sealing ring 205. As a result, a gap between the opening 204a and the opening 205b is blocked.
In a vacuum chamber of a vacuum vapor deposition apparatus, a vapor deposition material such as a metal, a metal oxide, or a metal compound is evaporated by heating (see FIG. 7). In this case, a vapor of the vapor deposition material generated from a vaporization source gets into an electron gun 252, which causes a problem in that it is difficult to continuously and stably generate a beam for a long time period. To solve this problem, various measures have been tried but failed.
For example, exhaust means for exhausting a gas in the vicinity of an exit hole of an electron beam has been provided like the vacuum vapor deposition apparatus shown in FIG. 7. Alternatively, a trap (not shown) for trapping the vapor of the vapor deposition material has been provided in front of the exit hole of the electron beam (see, Patent Document 3).
However, in the case of MgO, MgO gets into the electron gun in a significant amount, so that a sufficient effect cannot be obtained. Even if the vapor of the vapor deposition material can be prevented from getting into the electron gun, periodical maintenance such as an exchange of a filament is required.
Patent Document 1: Japanese Patent Application Laid-Open No. 2000-145980 (page 3, FIG. 1)
Patent Document 2: Japanese Patent Application Laid-Open No. 2004-360754 (page 4, FIG. 1)
Patent Document 3: Japanese Patent Application Laid-Open No. Hei 7-58832 (page 4, FIG. 1)